04-28-2012, 08:28 PM
In both Aperture and iPhoto (and Lightroom as far as I am aware) there is a concept called "round-tripping." Since I know iPhoto better than the other two, I'll explain the concept using that program, but I'm confident it works more-or-less the same on the others.
First, you set in the preferences that you'd like to use Photoshop CS5 as your "external editor."
Then you double-click on a photo you'd like to edit in iPhoto. Photoshop CS5 automatically opens up with a copy of your picture.
Once you're done editing in Photoshop, you simply save it. The saved photo is automatically sent back to iPhoto.
There's a REASON why all these photo programs "seal off" the photos into a "vault" and don't let you near them. It's to PREVENT exactly what you are trying to do -- mess with them without thinking and destroy or lose the "originals." You're supposed to work on COPIES of the pictures ONLY and not think about the originals AT ALL EVER. This workflow gives you the safety of original preservation AND the ability to go "back" to the "original" no matter how many changes you've made.
In all three programs, there is an easy option to store the photo library/vault on whatever drive you want. The main concept here is that you have to LET GO of the idea that YOU have to micromanage the organization of the pictures. You don't, just let the program do that. You also have to let go of the idea that you need to be able to access the "original." You don't. Ever. You can make a duplicate as easily as dragging a photo out to the desktop, so there's no need for you to muck about in the library.
As Dysfuntion says, once the program has set up its database, YOU DON'T MESS WITH IT. Because you don't have to. Everything -- absolutely EVERYTHING -- you might want to do with the pictures can be done from within the program.